1. Field of the Invention
The present invention relates to a method and system for making the flow of blood visible, whereby the flow of blood in a living body can be clearly seen.
2. Description of the Related Art
Ultrasonic diagnostic apparatuses are increasingly and widely used in the clinical field, not only for a tomogram (B mode image), but also for a Doppler analysis when for measuring a flow of blood in a heart lumen or a blood vessel. Particularly, recently the use of a color display of a real time blood flow velocity distribution, called color flow mapping, is rapidly spreading, since the display displays a flow of blood in a heart lumen as a color display, and thus a detection of a ventricular septal defect or valve failure can be made at a glance.
The real time image in this color flow mapping, however, displays only the following aspects. Namely, the blood flow at each position is displayed as a color code in response to the flow toward or flow away from an ultrasonic probe, or an amount of the component of the flow direction, for example, toward a direction corresponding to red (R), in an away direction corresponding to blue (B), and this amount corresponds to a brightness. Accordingly, a problem arises in that, when the real time images are continuously displayed, an image of the flow of blood is not obtained.
Recently, Motoyoshi Okujima, Shigeo Ohtsuki (Tokyo Institute of Technology), and Motonao Tanaka et. al. (Tohoku University) disclosed a blood flow vector generation process by which a vector distribution map is obtained in the real time flow from information on only a flow amount toward or a flow amount away from an ultrasonic probe (see Japan Ultrasonic Medical Society paper, May, 1986, 48-C-20, 48-C-21; November, 1987, 51-PB-35). As shown in this paper, each group obtains vector distribution maps at a plurality of phases. Nevertheless, when the maps are continuously displayed, the image of the real time blood flow cannot be seen.
Accordingly, a display of the flow of blood expressed by animated pictures is desired, as since the flow of blood relates to a blood pressure, at each position, and since the blood flow and the blood pressure are necessary for an analysis of the movement of a heart muscle or blood vessel, both the blood flow and the blood pressure distribution must be made visible.